Optimization of simulated 3-D effect through camera technique

ABSTRACT

Apparatus for optimization of a simulated three-dimensional effect for film or video includes at least one arcuate support rail and a trolley carrying a remotely controlled variable speed motor for moving the trolley along the rail. A camera mounting attached to the trolley is moveable horizontally and vertically with respect to the trolley and permits camera movement at a desired constant angular velocity at a specific and constant radius from the scene being recorded.

RELATED CO-PENDING APPLICATIONS

The following are applications that have been filed by one or both ofthese inventors relevant to this application: Ser. No. 07/327,039,"Method and Apparatus for Obtaining 3-D Images from 2-D Images, Usingthe Pulfrich Illusion"; and Ser. No. 07/359,154, "Method and Apparatusfor Improvements in the Photographing and Editing of Motion Pictures andVideotapes Utilizing the Pulfrich Illusion."

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to apparatus and methods for obtainingthree-dimensional images from two-dimensional images on either film orvideotape.

2. Prior Art

In the 1920s an optical illusion was discovered which has been referredto as the Pulfrich effect or illusion. In order to be elicited, itrequires constant motion under very defined conditions. It is able toutilize a single image rather than the conventional dual image. Itsdiscovery resulted in the fact that if one eye is shaded somewhat darkerthan the other, the exact amounts of which have been discussed in detailin two patents, U.S. Pat. Nos. 4,131,342 and 4,705,371, threedimensional (3-D) viewing is possible. In these two patents, respectiveinventors Leslie P. Dudley and Terry D. Beard discuss various aspectsconcerning the illusion of depth that is conferred on the individualviewing the phenomenon. The present investigators have confirmed thatonly one eye needs shading, and have discovered that the shading, asmanifested in a lens, need only be gray and/gradations there of.

Outdoor scenes facilitate the 3-D effect because there is considerablebackground. Nevertheless, in order to achieve good 3-D, it is alsonecessary to have very close (to the camera) foreground. Thiscombination with the subject inbetween makes ideal 3-D, whether a dualimage or the Pulfrich illusion is to be used.

During the nearly 70 years that have passed since the Pulfrich illusionwas discovered, little commercial use has been made of it, other thanDudley's attempt at animation, until Beard and others tried to capturethe illusion live, specifically, during the 1989 Pasadena Rose Paradeand then the Super Bowl halftime show of the same year.

The Pulfrich illusion requires constant motion in order for the in-depthperception to be achieved. Unfortunately, when viewed with angularcamera motion that is not constant in angular velocity or radius, orwith both eyes shaded with different neutral-density value filters, manypeople develop various types of eye strain. These may include doublevision or blurred vision, resulting in vertigo or headaches. The presentinvention enables people engaged in the shooting of stereoscopicillusions using the Pulfrich effect to overcome the problems inherent incapturing the illusion and, at the same time, to reduce the problemsassociated with viewing it. The shortcoming of the previous applicationswhen used for this purpose will be addressed, and the means ofovercoming such shortcomings disclosed.

SUMMARY OF THE INVENTION

In the past, 3-D pictures using the Pulfrich illusion have been shotwith the foreground as close as possible to the camera and thebackground going back a substantial distance, or to the horizon. Thisbecomes a critical problem (which has hindered the development of 3-Dtechnology) when used in confined areas, because stereoscopicvisualization has considerable limitations in confined spaces.

This limitation with respect to the Pulfrich illusion explains why theillusion was first used commercially to shoot the Rose Parade, the SuperBowl halftime, and outdoor commercials, all with very largeforeground-to-background distances involved.

If one could apply the Pulfrich method to an area as confined as awrestling or boxing ring, the possibilities for other uses would beenormous. Yet, having a camera directly operated by a cameraman whilethe camera moves continuously around the inside of, or is stationedwithin, a stationary ring presents impossible logistics. Minimally, theseats of the spectators would preclude having a dolly traveling in frontof them and obscuring their vision.

In the present invention, the camera can be suspended from the ceilingand all operations of the camera operated remotely. The camera moves inand out, up and down, while circularly traveling around the ring. Whenthe camera moves to its lowest position, minimal blocking of spectatorviewing occurs. This is an improvement over the prior art.

The cameraman operates the camera remotely by looking at a monitor, and,with one eye shaded, the cameraman sees 3-D illusion as it is beingshot. This is important to facilitate the best creative development ofthe event being photographed using the Pulfrich effect.

Additionally, a self-propelled vehicle, moving about on circular trackssurrounding the subjects being filmed or videotaped, may be employed. Itcarries a camera which itself does not move in or out, and whose focusremains fixed for certain shots. For flat footage, the camera can changelocation, zoom in and out, or simply remain still, all in one scene.This camera records action anywhere in the scene.

During circular motion shots, the camera always travels at uniform(constant) angular velocity. If more depth to the 3-D is desired, thecamera is speeded up. It is recognized that angular velocity exceedingthirty degrees per second will destroy the 3-D illusion and that angularvelocity of less than ten degrees per second will create little or no3-D illusion, this finding comprising part of the novelty of the presentinvention.

For any given radius of the camera to the object(-s) being photographed,as measured in the horizontal plane of the object(-s), that is, the trueradius, the linear circumferential speed of the camera has beendiscovered to require constant velocity to obtain optimal depth ofillusion. Stated differently, the angular velocity of the camera aboutthe object(-s) must be invariant, for constancy in the amount of 3-Dillusion, whatever the true radius of the camera to the object(-s) is.

All operational techniques discovered that elicit the 3-D illusion byusage of constant angular velocity, angular motion itself, and specificcircular motion with specific radii are essential discoveries of thepresent invention.

When it is desirable to shoot the video indoors in a confined space,with a single scene being used repeatedly (a wrestling match, boxingmatch, etc.), floor space will be limited and cannot be cluttered withvehicles and tracks. Furthermore, to have tracks on the floor withmoving vehicles on them in a small space will present a hazard to peoplewho are walking about when the room is not being used forcinematography. In addition, people might desire to use the space forother purposes when there is no filming or videotaping. Finally, to havea cameraman operate a camera directly in a confined space not onlyobstructs the view of spectators, but, also, might interfere with theaction of the scene being filmed. Yet, the camera must be instantlyready when action needs to be videotaped.

Thus, when other events need the shooting space, a fixed circularmonorail or dual tracks similar to a side-by-side pair of circularcurtain tracks can be attached to the ceiling with the lights placedinbetween and, in the case of an arena, drawn up when not in use.

Once the essential but cumbersome technique of obtaining circular cameramotion to elicit 3-D illusion is accomplished, as discussed above, thenext step in optimizing this 3-D illusion in a confined space is thelighting and color arrangement. Considerable lighting is required toelicit the 3-D illusion. Fortunately, the ceiling-held rails orcircular-moving arm are permanently fixed, so the lights can be attachedto the ceiling out of the way of the camera and left there. Illuminationapproaching the intensity of daylight is required, and in a confinedspace this is much less of a problem than on a sound stage or in anauditorium.

For optimal 3-D illusion, the lights illuminating the film stage willvary in intensity and in the timing of use. Light levels illuminatingthe scene nearest the camera are, typically, between 200 and 250foot-candles intensity. Light levels illuminating the middle groundshould be, typically, between 225 and 350 foot-candles intensity.Finally, light levels illuminating the background should be, typically,between 250 and 450 foot-candles intensity. Also, the timing of thelights optimizes the 3-D illusion. A number of the lights farthest fromthe moving camera will be, typically, sequentially shut off, while anumber of those closest to the camera which have not been in use willbe, typically, sequentially turned on; the sequencing of all lightsbeing dependent on the position of the moving camera and other factors.This operational technique of dynamically altering illumination toenhance 3-D illusion originates with the present invention.

Finally, the fixed position of the lights relative to the objects beingfilmed is consequential. Backlighting objects, whether in theforeground, the middle ground or the background optimizes the 3-Dillusion. The present investigators have built upon certain basicdepth/color perception discoveries, including those placed in the publicdomain in 1958 by Dr. Edwin Land, inventor of the Polaroid process. Theuse of backlighting to optimize simulated 3-D effect is a discovery ofthe present invention.

Selection and placement of color is essential to elicit the 3-D illusionin a confined space. Very bright lighting, combined with an easilyperceived distinction among the colors used and with a variety ofcolors, is necessary. Because filming is in a confined area, for optimal3-D, the colors must range over the entire visible spectrum, althoughnot every color is needed. Each of the layers of colors closet to thecamera is typically separated by a full color in the spectrum. Thisdiscovered sequence of colors takes advantage of the naturalchromostereoscopic effects of color created in the human brain. However,since the chromostereoscopic effect of the general 3-D illusion due tocolor is less than that created by the camera motion, the sequence ofcolors for color separation should be as diverse from each other aspossible. In other words, each layer of color should be a primary coloror a secondary color.

The contrast in colors can be enhanced by the use of colored lightsinterspersed with white lights to illuminate the film stage. The ratioof the chosen colored lamps to white lamps, each of the same wattage, istypically between 2:1 and 4:1, with specific ratios dependent on thecolor of the colored lights, the colors of the scene, and the locationof the colored lights vis-a-vis the camera. It is recognized that theratio of colored to white light is important, as too much colored lightwill reduce the foot-candles of illumination, thereby diminishing the3-D illusion.

Novelties of the present invention include the recognition of properselection and placement of color and color intensity, and thedevelopment of specific ratios of colored to white lighting at specificdistances to the camera.

DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a room viewed from the ceiling, with the room to havea videocamera rotate in a complete circle.

FIG. 2 illustrates in detail a videocamera adapted for movement alongcircular tracks as in FIG. 1.

FIG. 3 illustrates a section through a room in which the camera and thefilm stage are in the same vertical plane.

FIG. 4 illustrates a pair of viewing glasses with one lens darkened tofilter the light passing through it.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates camera A secured to and suspended from aluminumcamera support B, comprising columnar braces attached to a motorizedtrolley. Variable-speed motor C moves support B and camera A uponcircular tracks D. The entire assembly of camera A, support B, motor Cand tracks D is suspended from the ceiling from guy wires E.

FIG. 2 illustrates in detail the motorized trolley in FIG. 1.Variable-speed motor A is remotely controlled, and moves the trolleythrough connection to ribbed drive belt E. Belt E is connected to ribbedbelt groove casing D, which is bolted to V-groove drive wheel C. Wheel Csits upon the trolley track. As the trolley moves upon the track,restraint wheels G control the sway and, thereby, the focus of camera A,which, although not shown, is suspended by aluminum camera support B.Platform and hook F comprise means by which to slide camera A up anddown along support B. Turn screw H enables tilting of the trolley and,hence, camera A.

FIG. 3 illustrates the assembly of FIG. 1 in relation to the film stage.Tracks D are suspended directly above the film stage, with the tracksand the film stage forming concentric circles. Subject B, prop C, andbackdrop E are shown in relation camera A.

FIG. 4 illustrates a pair of viewing glasses with one lens darkened tofilter the light passing through it. The other lens is transparent. Thiscreates a 3-D illusion as the brain processes the image coming from eacheye, when these vieweing glasses are used in conjunction with constantangular motion of a camera at constant speed.

What is claimed:
 1. A process for optimizing a simulatedthree-dimensional effect for film or video comprising:illuminating ascene having foreground, middle ground and background portions with acombination of high intensity light sources having a preponderance of adifferent hue for each of said foreground, middle ground and backgroundportions, and having a pronouced distinction in hue between saidforeground and said middle ground, and between said middle ground andsaid background, said different hues to range over the entire visibleelectromagnetic spectrum, and said pronounced distinctions in hue to bedefined as the distinction between, at a minimum, a primary color andone of its corresponding secondary colors.
 2. The cinematographictechnique of claim 1 wherein the scene being filmed is backlit.
 3. Thecinematographic technique of claim 1 wherein said different hues andsaid pronounced distinction in hue are enhanced by a specificinterspersion of colored lights with the white lights for illumination,said interspersion typically comprising a ratio of colored lamps towhite lamps between 2:1 and 4:1, where all of said lamps are of the samewattage.
 4. Apparatus for optimization of a simulated three-dimensionaleffect for film or video when constancy of said effect is desired,comprising:at least one ARCUATE support rail, a trolley affixed movablyto said support rail, a remotely controlled variable speed motor affixedto said trolley for moving said trolley along said support rail, acamera mounting affixed to said trolley and movable horizontally andvertically with respect to said trolley, whereby a camera is moved at aconstant angular velocity relative to a scene to be filmed or recordedand wherein said angular velocity is defined as linear circumferentialspeed at a specific and constant radius from said scene, and saidangular velocity is between ten degrees per second and thirty degreesper second.